[0.15] fix incorrect worktree usage, release 0.15.1 (#714)

In #696, internal/git learned about worktres,
but the code that "opens" a worktree was using the wrong Git directory
when constructing the `Repository` object and `Worktree` objects.

This resulted in many operations, primarily `restack`
operating on the incorrect worktree.

Author: abhinav

.changes/v0.15.1.md

@@ -0,0 +1,3 @@
+## <a name="v0.15.1">v0.15.1</a> - 2025-06-25
+### Fixed
+- Fix several operations using the incorrect Git worktree when invoked from the non-primary worktree.

CHANGELOG.md

@@ -5,6 +5,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html),
 and is generated by [Changie](https://github.com/miniscruff/changie).
 
+## <a name="v0.15.1">v0.15.1</a> - 2025-06-25
+### Fixed
+- Fix several operations using the incorrect Git worktree when invoked from the non-primary worktree.
+
 ## <a name="v0.15.0">v0.15.0</a> - 2025-06-23
 ### Added
 - log short: Add `spice.logShort.crFormat` configuration option. This takes precedence over `spice.log.crFormat` for `gs log short`/`gs ls`.

internal/git/repo.go

@@ -91,12 +91,12 @@ func OpenWorktree(ctx context.Context, dir string, opts OpenOptions) (*Worktree,
 	if !ok {
 		return nil, fmt.Errorf("unexpected output from git rev-parse: %q", out)
 	}
-	gitDir, repoGitDir, ok := strings.Cut(out, "\n")
+	gitCommonDir, gitDir, ok := strings.Cut(out, "\n")
 	if !ok {
 		return nil, fmt.Errorf("unexpected output from git rev-parse: %q", out)
 	}
 
-	repo := newRepository(repoGitDir, opts.Log, opts.exec)
+	repo := newRepository(gitCommonDir, opts.Log, opts.exec)
 	wt := newWorktree(gitDir, rootDir, repo, opts.Log, opts.exec)
 	return wt, nil
 }

internal/git/repo_test.go

@@ -7,7 +7,10 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.abhg.dev/gs/internal/git/gittest"
 	"go.abhg.dev/gs/internal/silog/silogtest"
+	"go.abhg.dev/gs/internal/text"
 )
 
 func NewFakeRepository(t testing.TB, dir string, execer execer) (*Repository, *Worktree) {
@@ -26,6 +29,50 @@ func NewFakeRepository(t testing.TB, dir string, execer execer) (*Repository, *W
 	return repo, wt
 }
 
+func TestOpenWorktree_correctGitDirectory(t *testing.T) {
+	// This test verifies the fix for the worktree bug where OpenWorktree
+	// was using the wrong git directory when constructing Repository objects.
+	t.Parallel()
+
+	fixture, err := gittest.LoadFixtureScript([]byte(text.Dedent(`
+		as 'Test <[email protected]>'
+		at '2025-06-26T21:28:29Z'
+
+		mkdir repo
+		cd repo
+		git init
+		git add main.txt
+		git commit -m 'Initial commit'
+
+		# Create a worktree
+		git worktree add ../worktree -b feature
+
+		-- repo/main.txt --
+		main content
+	`)))
+	require.NoError(t, err)
+	dir := fixture.Dir()
+
+	ctx := t.Context()
+	mainWt, err := OpenWorktree(ctx, filepath.Join(dir, "repo"), OpenOptions{
+		Log: silogtest.New(t),
+	})
+	require.NoError(t, err)
+
+	wt, err := OpenWorktree(ctx, filepath.Join(dir, "worktree"), OpenOptions{
+		Log: silogtest.New(t),
+	})
+	require.NoError(t, err)
+
+	// Both should reference the same repository git directory
+	// This ensures the fix where gitCommonDir is used instead of gitDir
+	assert.Equal(t, mainWt.Repository().gitDir, wt.Repository().gitDir,
+		"repositories for both worktrees should share the same git directory")
+
+	assert.NotEqual(t, mainWt.gitDir, wt.gitDir,
+		"worktrees should have different git directories")
+}
+
 func TestExtraConfig_Args(t *testing.T) {
 	tests := []struct {
 		name string

testdata/script/branch_restack_worktree_conflict.txt

@@ -0,0 +1,62 @@
+# 'branch restack' with worktrees: main in wt1, feature in wt2, conflict resolution with 'gs rbc'
+
+as 'Test <[email protected]>'
+at '2025-06-26T21:28:29Z'
+
+# setup main repository (this will be wt1)
+cd wt1
+git init
+git add init.txt
+git commit -m 'Initial commit'
+gs repo init
+
+# create feature branch
+cp $WORK/extra/init.feature.txt init.txt
+git add init.txt
+gs bc -m feature
+gs trunk
+
+# create worktree wt2 for feature branch
+git worktree add ../wt2 feature
+
+# now change the main branch in wt1
+gs trunk
+cp $WORK/extra/init.main.txt init.txt
+git add init.txt
+git commit -m 'Change init on main'
+
+# go to wt2 (feature worktree) and attempt restack
+cd ../wt2
+git branch --show-current
+stdout 'feature'
+
+# restack the feature branch from wt2 (this will conflict)
+! gs branch restack
+stderr 'There was a conflict while rebasing'
+
+# resolve the conflict
+cp $WORK/extra/init.resolved.txt init.txt
+git add init.txt
+env EDITOR=true
+gs rbc
+
+# verify state in wt2
+git graph --branches
+cmp stdout $WORK/golden/graph.txt
+
+-- wt1/init.txt --
+initial init
+
+-- extra/init.main.txt --
+changed init on main
+
+-- extra/init.feature.txt --
+feature's init
+
+-- extra/init.resolved.txt --
+resolved init content
+
+-- golden/graph.txt --
+* b05ac5a (HEAD -> feature) feature
+* e6e3766 (main) Change init on main
+* 26ee912 Initial commit